HomeMy WebLinkAboutWPO202100035 Correspondence 2021-09-17A.
SEH
Building a Better World
for All of Us°
September 9, 2021
Albemarle County
401 McIntire Road
Charlottesville, VA 22902
RE: Rivanna Water and Sewer Authority
Airport Rd. Pumps Station
SEH No. RIVAN 153082 14.00
Enclosed is the second submission for the Virginia Stormwater Management Program (VSMP), WP02021-
00035, Airport Road Pump Station Project. The electronic application submittal includes:
• Responses to comments provided on 08/18/2021 and commits through email.
• Erosion Control Plan & Stormwater Management Plan
• Stormwater Pollution Prevention Plan
• Site Plan Sheets
The Stormwater Pollution Prevention Plan is submitted without the designation of the Operator/Permittee. This
information will be completed by the contractor once the project is awarded. It is the intent for the contractor to
submit/obtain the grading permit, and at that time, the missing information in the Stormwater Pollution Prevention
Plan will be completed.
If you have any questions with the application, you can reach me at 507.508.4707, or mmccartvCilsehinc.com.
Sincerely,
SHORT ELLIOTT HENDRICKSON INC.
Maria McCarty
Engineer
MNT
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Engineers I Architects I Planners I Scientists
Short Elliott Hendrickson Inc., 3535 Vadnais Center Drive, St. Paul, MN 55110-3507
SEH is 100% employee -owned I sehlnc.com 1 651.490.2000 1 800.325.2055 1 888.908.8166 fax
i
Engineering Review Comments
Page 2 of 11
COMMUNITY DEVELOPMENT DEPARTMENT Telephone: 434-296-5832
WWW.ALBEMARLE.ORG
VSMP Permit Plan Review
Project:
Airport Road Pump Station Project
Project file number:
WPO2021-00035
Plan preparer:
Brad Weiss, PE, Project Engineer — Short Elliot Hendrickson, Inc. (SEH)
bweiss(a),sehinc.com
3535 Vadnais Center Drive, St. Paul, MN 55110
Owner or rep.:
Michelle Simpson, PE [ msimpson e rivanna.org ]
Rivanna Water and Sewer Authority, 695 Moores Creek Lane
Charlottesville, VA 22902
Plan received date:
30 June 2021
Date of comments:
18 Aug 2021
Reviewer:
John Anderson, PE
County Code section 17-410 and Virginia Code §62.1-44.15:34 requires the VSMP authority to act on any
VSMP permit by issuing a project approval or denial. This project is denied for reasons listed below. The
VSMP application content requirements can be found in County Code section 17-401.
A. Stormwater Pollution Prevention Plan (SWPPP)
1. The SWPPP content requirements can be found in County Code section 17405. A SWPPP must contain
(1) a PPP, (2) an ESOP, (3) a SWMP, and (4) any TNIDL measures necessary.
1. SWPPP / Ref. p. 134 of 160p. initial plan submittal, request Applicant revise, as follows:
a SWPPP Sec. 1 / Registration Statement: Complete Registration Statement:
i. Sec. I/A.,B.,C (Recommend check C. box `yes')
ii. List Sec. II.B. Address for locational/navigational purposes as Berkmar Drive Ext., North
Terminus
iii. Complete Sec. IV.B. — Estimated project dates
iv. Complete Sec. VI: Print /sign /date
SEH Response: Draft Registration statement with the following sections completed: 11, IV, and
V. Sections 1, III, and IV shall be completed by the contractor after bids are
awarded.
b. SWPPP Secs. 4-5: Update with revised plans
SEH Response: Updated
a SWPPP Sec. 6.
i. A. -Exhibit /Please revise to clarify (initial) locations of.
1. Rain gauge
2. Solid waste dumpster (if any)
3. Portable sanitary facility (ports John)
4. Paved construction entrance (may not use Berkmar Drive Ext. as PCE)
Engineering Review Comments
Page 3 of I I
5. On -site fuel storage (if any)
SEH Response: Note was added to the plans instructing field locations of requested be added
to the plans.
ii. E. -Please name individual responsible for PPP
SEH Response: Will be completed by the contractor after bids are awarded.
d. SWPPP Sec. 8 -Please name individual responsible for SWPPP compliance inspections; may be
qualified RWSA, SEH, or contractor personnel. Required to receive Grading Permit, but not
required for WPO plan approval.
SEH Response: Will be completed by the contractor after bids are awarded.
e. SWPPP Sec. 9, Signed Certification: Provide title /sign /date.
SEH Response: Will be completed by the contractor after bids are awarded.
B. Pollution Prevention Plan (PPP) — See above, Sec. 6.
The PPP content requirements can be found in County Code section 17-404.
SEH Response: Note was added to the plans instructing field locations of requested be added
to the plans.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan is disapproved for reasons listed below. The stormwater management plan content requirements can be
found in County Code section 17-403.
1. C12 C13
a. Ref. Engineering review comments, SDP202100056 (8/4/21), and revise proposed grade
accordingly.
SEH Response: Site plan comments incorporated.
b. Add linework to graphically explicitly indicate upslope point where defined Swale begins.
SEH Response: Swale removed with grading changes for ELS.
c. Label bioretention basin, L x W, in plan view.
SEH Response: Length of ELS noted on plans. Width noted in section.
d. Label length of stone pre-treatment, each end of basin.
SEH Response: No longer applicable with change to ELS.
e. List ft' media required for bioretention basin construction. [ Recommend number pages of
Calculation Packet, and reference relevant pg. in calc. packet.]
Engineering Review Comments
Page 4 of 11
SEH Response: No longer applicable with change to ELS.
f. Revise plan view of basin to show buried stone storage at south end of basin, similar to the way
buried stone storage is shown along west edge of basin.
SEH Response: No longer applicable with change to ELS.
g. Label all basin elevations, including base of 24" storage area, base of fill media, pea gravel, etc.
SEH Response: Elevations included in section of ELS w/ forebay.
h. Revise `bottom elevation' label to read `top of fill media.
SEH Response: No longer applicable with change to ELS.
i. Include Construction Record Drawings (As -built) for VSMP on the plans:
httos://www.albemarle. ore/home/showoublisheddocument/3381 /637327510536700000
SEH Response: Provided notes included on ELS drawings.
j. Include BMP clearinghouse bioretention installation (8.2), construction inspection, first -year
maintenance operations (9.2), and maintenance inspections (9.3) information on the plan.
SEH Response: Penitent BMP clearing house language for installing, inspecting, and
maintenance included on ELS drawings.
k. Include attached periodic bioretention inspection checklist on the plans.
SEH Response: Periodic inspection checklists for ELS included on drawings.
1. Indicate locations of 3 trees and 15 shrubs in plan view, identify using planting legend symbols.
SEH Response: No longer applicable with change to ELS.
2. Note: A 160-p. composite document was submitted: Application, certification (Miles B. Jensen, VA PE),
proprietary document (TOC, Site Description, ESC Plan, SWM Plan, Tables, Appendices). 20-sheet plan
comprises last pp. of the document.
a. Please divide this document into separate submittals: Application, Calculation Packet (incl.
USDA-NRCS soils map, drainage map/s, pre- post -condition, etc.), SWPPP, WPO plan.
SEH Response: Application divided for submittal.
b. Additional /specific:
i. PG. 9 (of 160-p..PDF): Revise ref. at 3.1.1 to require a paved construction entrance,
rather than a temporary stoned construction entrance. See comment/s elsewhere
requesting ACDSM paved wash rack detail be placed on plans.
SEH Response: Section updated with paved construction entrance.
it. PG. 14: 4.2.2 Ref. to Flood Protection — East discharge to meeting requirements for
9VAC25-870-66.C.2.b. indicates discharge to a (manmade) storm conveyance system
that experiences periodic flooding. As discussed 8/17/21 (Weiss -Anderson), it is unclear
Engineering Review Comments
Page 5 of 11
that proposed east discharge from the bioretention basin is to a manmade system. Please
clarify (via narrative, note, graphic linework, labels) that bioretention basin discharge is
to an existing manmade stone conveyance system that experiences periodic flooding.
SEH Response: Evaluation for the east drainage area updated to meet 9VAC25-879-66.d with
the released peak flow per linear foot for the 10-yr 25-hr event less than the
pre -condition, as discussed in 813112021 meeting.
iii. Also, 4.2.2 makes ref. to 2-yr storm event peak discharge of 0.92 cfs, with runoff velocity
of 2.86 ft/s. Plan must indicate discharge is to a manmade conveyance system, and is
non -erosive, or is to a defined channel (as indicated by field -run or GIS contours) or to a
natural receiving stream. 2-yr event discharge of 0.92 cfs at 2.86 ft/s to undefined
parallel contour slopes may result in near- or long-term erosion issues for downslope
storage facility. Revise design to show discharge (to East) is to a manmade conveyance
system. As discussed 8/17, RWSA site elevation is nearly 100' higher than U.S. Rte, 29.
Engineering must evaluate possible impact of site discharge on downstream receiving
properties.
From county GIS:
SEH Response: Evaluation for the east drainage area updated to meet 9VAC25-879-66.d with
the released peak flow per linear foot for the 10-yr 25-hr event less than the
pre -condition, as discussed in 813112021 meeting.
iv. A public drainage easement is required between SWM facility outfall and receiving
manmade system, or to point site discharge reaches a receiving stream [Ref. 18-32.7,4.2].
SEH Response: Evaluation for the east drainage area updated to meet 9VAC25-879-66.d with
the released peak flow per linear foot for the 10-yr 25-hr event less than the
pre -condition, as discussed in 813112021 meeting. No offsite public drainage
easement is required.
PG. 41 (Postcondition —East drainage)
1. Construction sequence:
a. At item 1, and wherever plan references a gravel or stone construction
Engineering Review Comments
Page 6 of 11
entrance, edit to read paved construction entrance with spray wash.
SEH Response: This page is an exhibit only. Construction sequence language removed.
b. At item 4, revise sequence to clarify that bioretention basin cannot be
constructed unless all upslope disturbed areas are stabilized. Items that
follow item 4 include rough grading, grading, building and utility
construction, each with land disturbance.
SEH Response: This page is an exhibit only. Construction sequence language removed.
2. Erosion control:
a. At item 6, delete reference to University of Virginia.
SEH Response: This page is an exhibit only. Erosion control language removed.
b. Re. item 7, show stockpile area, graphically, provide temporary ESC
measures to limit sediment transport from soil stockpile.
SEH Response: This page is an exhibit only. Erosion control language removed.
3. General notes:
a. At item 1, please clarify. Why should basin require restoration? What
VDOT specification supersedes VA DEQ design specification?
SEH Response: This page is an exhibit only. General notes language removed.
b. At item 2, reference VESCH, not VDOT specification.
SEH Response: This page is an exhibit only. General notes language removed.
c. At item 3, please reference VESCH, not VDOT.
SEH Response: This page is an exhibit only. General notes language removed.
d. At item 3, grading beyond plan -approved limits of land disturbance is
impermissible. If Applicant anticipates grading beyond plan LOD,
recommend revise LOD to accommodate anticipated grading need.
SEH Response: This page is an exhibit only. General notes language removed.
vi. PG. 42 (Postcondition -bioretention basin)
a. Clarify note that reads ` 130 LF gravel basin access drive restore with
erosion matting following removal.' Permanent SWM facility requires
permanent access, which may be turf, 10' wide (Min.), 20% slope
(Max.).
SEH Response: This page is an exhibit only. Language removed.
b. `See Sheet C 12 for restoration details' label is confusing. Restoration
suggests bioretention basin is damaged, in need of restoration. Clarify.
Engineering Review Comments
Page 7 of 11
SEH Response: This page is an exhibit only. Language removed.
Postcondition may claim forest /open space land cover only with deed
of dedication of platted forest /open space easement. Submit easement
plat application, or revise design, calculations, VaRRM.xIs to eliminate
postcondition FOS land cover (0.16 Ac.).
SEH Response: Forest/open space is not included in post condition VaRRM.xis.
vii. PG. 44 (Postcondition—West drainage)
1. Postcondition may claim forest /open space land cover only with deed of
dedication of platted forest /open space easement. Submit easement plat
application, or revise design, calculations, VaRRM.xIs to eliminate
postcondition FOS land cover (0.09 Ac.).
SEH Response: Forest/open space is not included in post condition VaRRM.xis.
viii. PG. 48 (VaRRM.xIS)
1. Provide Site tab data /image from DEQ Virginia Runoff Reduction Method New
Development Compliance Spreadsheet.
SEH Response: Site tab included.
ix. PG. 60/other SCS Graphical peak discharge computations that rely on VaRRM.xIs may
need to be revised if VaRRM.xls is revised to eliminate postcondition forest -open space.
SEH Response: Quality calculations are the only computations that rely on VaRRM.xis.
x. PG. 64 /Required storage volume, (Vs) may increase if SCS graphical peak discharge
values change.
SEH Response: Quality calculations are the only computations that rely on VaRRM.xIs.
xi. PG. 68 pipe j`lowingfull, storm drains at Laurel Park Ln: Clarify whether table values
exclude any runoff expected to reach storm drains at Laurel Park Ln. That is, storm
drains at Laurel Park Ln. were designed to serve separate, earlier development at HTC.
Airport Road pump station analysis must include all sources that contribute runoff to the
existing storm drains. Please provide explicit calculations that clearly identify sources of
runoff to existing storm lines, and that indicate the existing storm drains at Laurel Park
Ln. serve prior development and can accommodate additional Airport Road pump station
runoff within the full -flow capacity of existing storm pipes to project limits of analysis, in
an open -channel non -pressurized state.
SEH Response: Calculations include all drainage to the storm drains on Laurel Park Ln. Storm
drain locations added to Exhibits to clarify.
D. Erosion and Sediment Control Plan (ESCP)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan
is disapproved for reasons listed, below. The erosion control plan content requirements can be found in
County Code section 17-402.
Engineering Review Comments
Page 8 of 11
1. Revise to include WPO-related sheets only, please remove sheets C14, DCO2, DC04.
SEH Response: Sheets C14, DCO2, and DC04 removed.
2. Revise plan title to include reference to WP0202100035.
SEH Response: Reference in plan title to WP0202100035 added.
3. Provide conventional plan title sheet that includes:
a. Adjacent parcel information, including:
i. Deed book -page reference.
ii. Vicinity map, and no greater than 1"=2,000'
iii. Owner, related zoning (ZMA) or site (SDP) plan.
b. PE -seal (sign /date)
c. Note regarding future VDOT Berkmar Drive Ext. project.
d. Note regarding proposed length and location /alignment of new 24" DI water main.
e. Limits of disturbance (x.xx Ac.), to include the approximate linear Area of Land Disturbance
associated with installation of approximately 4500 LF of 24" water main.
f Note: ESC measures require bond. ESC measures for linear portions (24" water main) on off -site
parcels not owned by RWSA require those owners be party to the bond, unless a contractor posts
the WPO plan bond. RWSA should plan accordingly, to either arrange signature information
/signatures of owners (of all parcels 24" water main transits) on the WPO plan (ESC) bond, or, to
require RWSA contractor post WPO plan bond (ESC/SWlv1).
SEH Response: Plan title sheet added.
4. Note: (Temporary construction) easements appear to be required to constructlinstall 24" DI water main
beyond public RW, beyond RWSA tax map parcel 32-41A2. Acquire and record temporary construction
easements, as needed, to install 24" DI water main. Provide Engineering copy of recorded easements.
SEH Response: Permanent easement obtained for work within kohl's property. Remaining
work within VDOT ROW and additional easements are not required.
5. C05: Please check label, which may require edit, or deletion.
BERKMAR DR
BURY Wr .VEN -
MT UB.EOV.fl V.B.
CONNECTTO"NY 24-
I &TRMUO
SEH Response: Acknowledged.
6. C09: Please title this sheet `site layout' since a WPO plan cannot approve a site plan.
Engineering Review Comments
Page 9 of 11
SEH Response: C09 title changed to site layout.
7. Reference and incorporate SDP202100056 Engineering review comments in revised WPO plan, see
comments d. 8/4/21.
SEH Response: Sheet updated with site plan comments.
8. CIO
a. Include paved wash rack detail from p.8, ACDSM,
httpS7//www.albemarle.orvJHome/ShowDocument?id=270
SEH Response: Paved wash rack added.
b. Provide and acquire public drainage easement across 32-41H1 to such point that concentrated
bioretention basin discharge reaches manmade pipe network, or a natural receiving stream. Proposed
design shows discharge to parallel slope contours, without receiving channel, with 40-ftvertical
interval to a downslope storage facility, with approximately half this distance across managed steep
slopes. Routing ACSA pump station bioretention basin discharge across adjacent downslope parcel
with no receiving or manmade pipe system is impermissible. Please notify Engineering of deed bk.-
pg. of off -site public drainage easement, and include bk.-pg. ref on revised WPO plan.
SEH Response: Evaluation for the east drainage area updated to meet 9VAC25-879-66.d with
the released peak flow per linear foot for the 10-yr 25-hr event less than the
pre -condition, as discussed in 813112021 meeting. No offsite public drainage
easement is required.
C. Please include more deliberate grade lines to clearly indicate a proposed ditch at 130 LF gravel
basin access drive leading to bioretention basin (permanent SWM facility).
SEH Response: Swale removed with grading changes for ELS.
d. A SWM facility cannot be built with initial grading, rather, permanent SWM facilities are built once
all up -slope contributing drainage areas disturbed by construction, are stabilized. A sedimenttrap may
be required (item discussed by county with Brad Weiss, 8/17/21). Show, provide and design a trap, if
temporary sediment trap is warranted —likely best location is future location of bioretention basin.
Include all relevant design criteria, for example: wet/dry storage required, provided, side slope (2:1,
etc.), and area draining to tap (x.xx Ac.). If sediment trap is not proposed, confirm that upslope
contributing drainage area does not exceed 100 LF slope/ft. silt fence. Note: Item discussed with
Brad Weiss, 8/17, telecon, 3:10-3:50pm Q. Anderson).
SEH Response: Modified mud trap proposed with wire reinforced silt fence.
e. Revise p. 11 of 160-p. submittal (Erosion Control Sequence) to include narrative discussing
coordination of bioretention basin installation (if retained with revised design) with site
stabilization.
SEH Response: Erosion control sequence updated with ELS installation after stabilization.
Please remove bioretention basin (or other SWM facility) from ESC plan sheet/s. Show SWM
facilities on a SWM plan sheet.
SEH Response: SWM shown on SWM plan sheet. Contours for the ELS will appear on the E&S
Engineering Review Comments
Page 10 of 11
sheet.
g. Include note that bioretention basin may not be constructed until all upslope contributing drainage
areas are stabilized. Include note on CC 13 as well.
SEH Response: Note added for the ELS.
9. CII
a. Show grading and required ESC measures and permanent stabilization sufficient to establish padsfor
anticipated future ground storage tank/s since these are immediately adjacent and just upslopeof the
proposed bioretention basin. If bioretention is installed prior to future tank grading, then future tank
grading is likely to compromise (blind) soil medium, and SWM facility performance, which may
contribute to avoidable effort and expense, in the future.
SEH Response: GSR linework removed and note added to clarify.
b. Show soil stockpile location listed at p. 11, 3_3. Erosion Control sequence, item 3. of 160-p. initial
submittal .PDF.
SEH Response: Stockpile location added.
Process:
After approval, plans will have to be bonded. The bonding process is begun by submitting a bond estimate request
form and fee to the Department of Community Development. One of the plan reviewers will prepare estimates and
check parcel and easement information based on the approved plans. The County's Management Analyst will
prepare bond agreement forms, which will have to be completed by the owner and submitted along with cash,
certificates or sureties for the amounts specified. The agreements will have to be approved and signed by the County
Attorney and County Engineer. This may take 2-4 weeks to obtain all the correct signatures and forms.
Stormwater Management Facilities Maintenance agreements will also have to be completed and recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will have to be submitted along with court recording fees.
Permanent SWM facilities and public drainage easements require deeds of dedication. Deeds must be recorded prior
to VSMP/WPO plan approval. A separate easement plat submittal (Application) is required for public drainage or
SWM facility easements, which, for the moment, are proposed with Airport Road pump station VSMP.
After bonding and agreements are complete, county staff will enter project information in a DEQ database for state
application processing. DEQ will review the application information based on local VSMP authority approval. At
this time, the DEQ portion of the application fees will have to be paid directly to the state. For fastest processing,
this is done electronically with the emails provided on the application. DEQ should notify applicants with
instructions on how to pay fees. When DEQ approves the application, they will issue a permit coverage letter. This
should be copied to the county.
After DEQ coverage is issued, via the coverage letter, the County can hold a pre -construction conference.
Applicants must complete the request for a pre -construction conference form, and pay the remainder of the
application fee. The form identifies the contractor and responsible land disturber, and the fee remaining to be paid.
This will be checked by county staff, and upon approval, a pre -construction conference will be scheduled with the
Engineering Review Comments
Page 11 of 11
County inspector. At the pre -construction conference, should everything proceed satisfactorily, a joint VSMP and
grading permit will be issued by the County so that work may begin.
County forms can be found on the county website under engineering applications;
https://www.albemarle.org/goveniment/communily-development/apply-for/en ing Bering-apolications
Please feel free to call if any questions: 434.296-5832 -x3069
Thank you
I Anderson
WP0202100035_Airport Road Pump Station_081821